Extraction[M]: Optimized for performance

Avoided repeated data extraction with reciving an instance
User[M]: Optimized for performance

replaced python list O(n) searches with incrementing index

Fixed module dependency and initalization sequence
Narith: Handling corrupted packets
Protocols[M]: added checksum method for IP, TCP
User[M]: Re-reading pcap files by resetting a session
Pcap.py: Fixing minor bug concerning pcap records
Icmp.py: Supported Icmp protocol

IP.py: added Icmp to next protocols

Eth.py: handle unsupported next protocols
Merge branch 'python'